The comments about good sub-base are dead on. Even if you put down an aggregate base, it should be rolled or hand tamped. Aggregate bases can be compacted up to 25% of their initial thickness. Concrete is usually specified as 6 bags portland per cu. yd. with no more than 6 gallons of water per bag (36 gallons per yard). The water is the key to cracks. The slab as it cures will develop tremendous shrinkage forces internally. The lower the water/cement ratio the less shrinkage and the fewer the cracks. Normally slabs are poured in 20 ft squares to control cracking but cracks do occur anyway, usually a foot away from the control joint. The fiber mesh folks made huge claims of strength when the product was introduced in the late 6o's. Most of the claims have proven to be false. The only accepted benefit of fiber mesh is that it absorbs or disapates the internal shrinkage forces thus helping to prevent cracks. Flexural strength, the ability to carry loads is usually attained by the addition of steel reinforcing bars. The usual spacing for a 6" thick slab on a good sub base would be #3 bars at about 12" centers each way. If the slab is to carry unusually heavy loads, the bars need to be #4 or thicken the slab another 2 inches. The bars to be effective must be held at a point at least 2" clear of the base not to exceed 3". This usually means driving bars to support the mat or buying bar chairs to hold the mat at the proper height in the slab. The bars must be tied together at at least every other intersection to prevent them from being displaced by pouring the concrete. In summary the best way to prevent cracks is to isolate immoveable surfaces, i.e. columns and walls and limit the water/cement ratio. Pour it as dry as can be worked. Wet self leveling concrete will in a month look like a spider web of cracks. Good luck with your project.......
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Listening to Your Tractor - by Curtis Von Fange. Years ago there was a TV show about a talking car. Unless you are from another planet, physically or otherwise, I don’t think our internal combustion buddies will talk and tell us their problems. But, on the other hand, there is a secret language that our mechanical companions readily do speak. It is an interesting form of communication that involves all the senses of the listener. In this series we are going to investigate and learn the basic rudimentary skills of understanding this lingo.
... [Read Article]
Latest Ad:
2022 John Deere 5045E, 4wd, front end loader and 3rd function with grapple. 120 hrs, 55k new, must sell
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
